Work piece storage place for lapping machines



Oct. 16, 195$ s. MESSERSCHMIDT 2,766,556

WORK PIECE STORAGE PLACE FOR LAPPING MACHINES Filed July 25, 1951 2 Shets-Sheet 1 ATTORNEY Get. 16, 1956 S. MESSERSCHMIDT Filed July 25, 1951 2 Sheets-Sheet 2 x y l2 J n l3 i i8 44 4| 4s 40 X I I6 22 I E i I l0 l5 6 2o 2s l 24- ZZ/ f 35 I 3| 2 l 36 a? 2 33 a4 i 5 E a E INVENTOR SEBASTIAN MESSERSCHMIDT BY 921M ATTORNEY Unite Stats WORK PIECE STORAGE PLACE FOR LAPPING MACHINES The invention relates to a work piece storage place adapted to be attached to a lapping machine thereby considerably increasing the capacity of such machine.

The lapping machines known up to now have a certain limited capacity corresponding to the diameter or size of their lapping wheels. The lapping operation has the purpose to work simultaneously as many work pieces as possible and to attain, in addition to a good surface, uniformity and equal work piece tolerances with a small detachment of cuttings. Generally a set of work pieces, the number of which depends on the size, and therewith on the capacity, of the lapping wheels is simultaneously lapped. These work pieces of one set have all the same tolerances.

In the mass production or manufacture where the lapping machine does not work only one set of work pieces but continuously new sets are fed, the final tolerance is determined by the variety of the individual sets relatively to each other. Therefore, there is an obvious need to effectively increase the capacity of the lapping wheel and therewith of the lapping machine as much as technically possible.

The present invention starts from the existing limits of such possibility. According to the present invention the Work pieces are continuously removed from the lapping wheels and guided to a storage place of any suitable size whereupon they are returned to the lapping wheel in the same succession in which they were removed. Such an arrangement renders it possible to work a multiple of the work pieces corresponding to the pre-existing capacity of the machine in one operation, so that the same conformity and tolerances may be attained for any number of work pieces without being dependent on the capacity of the lapping wheels.

In the special case of grinding and lapping balls, the idea is already known to remove the goods to be lapped from the lapping Wheels during the operation thereof, to cause the balls to run over a magazine having the shape of a blade wheel and to return the balls thereafter to the lapping wheels. This kind of magazine, however, has the following disadvantages which are generally obviated by the present invention.

(1) Such magazines are only adapted for Work pieces which need not be fed to the lapping wheels again in the same position and on the same side thereof.

(2) By the free gravitational fall the work pieces strike against each other along the worked or lapped surfaces.

(3) Small work pieces may stick fast in the magazine, thereby failing to participate in some circulations, i. e., thereby failing to undergo all lapping operations, and do not come up again under the lapping wheel till later on. These work pieces are, therefore, still thicker than those which pass the lapping operation regularly. They influence the lapping operation very unfavorably by their dimension compared with that of the other work pieces.

According to the present invention the Work pieces are positively seized and pushed onto the storage place atent 2,766,556 Patented *Oct. 16, 1956 without their position being changed and are afterwards returned continuously and also positively to the lapping wheels.

According" to another feature of the present invention the storage place consists of an annular plate the upper surface of which lies in the same plane as the upper surface of the lower lapping wheel, a scraper being provided guiding the work pieces continuously and positively from the lapping wheels to the storage place and vice ver'sa.

Further objects, features, and advantages of the present invention willbecome more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention and wherein Figure 1 is a partial cross-sectional view through the lapping wheels and the annular work piece feeding and receiving disk in accordance with the present invention taken along lines 1-1 of Figure 2 with certain parts omitted for the sake of clarity,

Figure 2 is a top plan view of Figure 1 with certain parts omitted for the sake of clarity, and

Figure 3 is a cross-sectional view taken along lines 3+3 of Figure 2.

Referring now more particularly to the drawing wherein like reference numerals are used throughout the various views to designate like parts, reference numeral 10 designates the frame or base plate which at the same time may form a housing for the motor or the like. A central upright member 11 and two diametrically opposite upright members 12 and 13 are securely mounted on the top of the base plate 10. The lapping machine itself as to the frame thereof and rotating elements on which the parts in accordance with the present invention may be mounted and by which these parts may be driven, may be of any suitable conventional structure, such as, for instance, shown in United States Patent No. 1,371,854 to C. D. Buck of March 15, 1921, entitled Grinding Machine.

The lapping machine comprises an upper lapping wheel 14, a lower lapping wheel 15, and an annular work piece feeding and receiving disk 16 forming a storage space. The upright members 11, 12 and 13 may be reinforced by a transverse connecting cross member 17 to impart greaterrigidity to the frame. The upper lapping wheel 14 which is stationary may be mounted to the central upright member 11 in any suitable manner, as, for example, by resting on a flange 18 formed integral with the upright member 11. An opening 19 in the hub portion of the upper lapping wheel 14 may serve to accomrnodate any suitable fastening means such as, for example, a set screw. 7 I p The lower lapping wheel 15 is rotatably supported on the central upright member 11 by means of a suitable bearing 20. The lower lapping wheel which is concentric with the upper lapping wheel 14 is mounted for rotation about an axis a-a. The annular disk 16 which is rotatable about an axis bb is, therefore, ecce'ntricall'y mounted as regards its rotation with respect to that of the lower lapping wheel 15 since the two axes a a and b-b are displaced as is clearly visible from Figure 1.

The drive for rotation of the lower lapping wheel 15 and of the annular disk 16 may be realized in any conventional manner. For example, the lower lapping wheel 15 may be provided with an external ring gear 21 while the annular disk 16 may be provided with an internal ring gear 22. Pinions 23 and 24 suitably supported on the frame 10 are in meshing engagement with the ring gears 21 and 22 respectively. Any suitable driving means such as an electric motor 25 may be used to drive the pinions 23 and 24. A conventional linkage consisting of belts 26, pulleys 27 mounted on shaft 28 which is rotatably supported within the frame 10, bevel gear 29 mounted on shaft 28 which is in meshing engagement with bevel gear 30 which in turn drives spur gear 31 mounted on the common shaft 32 and which transfers the drive through meshing gears 33 and 34 to the shafts 35 and 36 on which the pinions 23 and 24 are securely mounted may be used to accomplish the rotation of the lower lapping wheel 15 and of the annular disk 16. It should be noted that by this arrangement the two parts, namely, the lower lapping wheel 15 and the annular disk 16 rotate in opposite directions, the former, for example, in the direction of the arrow A, and the latter thereupon in the direction of the arrow B. Suitable bearings may be provided wherever necessary which, for the sake of simplicity, are not shown herein.

A scraper 37, the function of which will be described more fully hereinafter, is securely fastened to the upper lapping wheel in any suitable manner, for example, by means of bolts 38 and tubular sleeves 39 or the like forming spacers. The scraper 37 is, therefore, also stationary since it is rigidly connected with the stationary upper lapping wheel 14.

The annular disk 16 may be provided with an outer upright wall or rim 40 which may be secured thereto for common rotation therewith.

If so desired, a further upright wall or rim 41 may be provided along the inside of the annular disk. This latter wall 41, however, is stationary and is supported in any suitable manner on the frame and the upright members 11, 12 and 13.

In order to enable the passage of the work pieces 43, the upright inner wall 41 is provided with an opening 42 (Figure 2).

The upper and lower lapping wheels 14 and 15 are so arranged that the upper surface 44 of the lower lapping wheel 15 is flush with the upper surface 45 of the annular disk 16.

Operation In operation, the upper lapping wheel 14 and the scraper 37 are stationary, the lower lapping wheel rotates in the direction of the arrow A and the annular disk 16 forming the storage space rotates in the direction of the arrow B. During such rotation of the lower lapping wheel 15 and of the annular disk 16, the work pieces 43 are removed from the space between the lapping wheels 14 and 15 by means of the stationary scraper 37 rigidly secured to the upper lapping wheel 14 and are thereby guided onto the plate or annular disk 16. The work pieces 43 thereby move in the direction of the narrow C when leaving the space between the lapping wheels and are thereupon carried around by the annular disk 16 in the direction of the arrow B. The work pieces are then brought to the rear side of the scraper 37 which returns them positively in the direction of the arrow D into the space between the lapping wheels 14 and 15.

The work pieces 43, therefore, under no circumstances fall and are removed from and restored to the space between the lapping wheels 14 and 15 in essentially the same position. Furthermore, the scraper 37 assures that none of the work pieces 43 fails to undergo a lapping operation so that conditions are established that all work pieces are subjected to a uniform lapping operation.

The annular disk or plate 16 may be adjustable with respect to the lapping wheels 14 and 15, especially when balls or similar work pieces are to be lapped. It may thereby be attained that the work pieces 43 change their positions without the accompanying disadvantages that the work pieces fall or that the individual work pieces stick as it was the case with the magazine used heretofore. It is very suitable to arrange the storage place formed by the annular disk 16 around the lapping wheels 14 and 15 as a relatively large storage place is made available thereby without influencing the accessibility of the lapping machine.

Having thus particularly described the nature of my invention and the manner in which the same is to be performed, I claim:

1. A lapping machine comprising a frame, a pair of spaced lapping wheels arranged in horizontal planes one over the other in spaced relation and of which the lower wheel is rotatably mounted and the upper wheel is stationary, an annular work piece feeding and receiving disc mounted to rotate in a horizontal plane with the upper surface thereof coinciding with the upper plane of said lower wheel, means for supporting said upper wheel on said frame, means for rotating said disc, means for rotatably supporting said lower wheel on said frame, means rotating said lower wheel, and a scraper secured to the upper wheel and extending approximately radially toward and over the upper surface of the feeding and receiving disc to positively remove and continuously feed the work pieces from and between the lapping wheels, said scraper returning the work pieces again to the lapping wheels in the same succession in which they were removed.

2. A lapping machine comprising a frame, a pair of spaced lapping wheels arranged in horizontal planes one above the other in spaced relation and of which the lower wheel is rotatably mounted and the upper wheel is stationary, an annular work piece feeding and receiving disk, mounted to rotate in a horizontal plane with the upper surface thereof coinciding with the upper plane of said lower wheel, means for supporting said upper wheel on said frame, means for rotating said disk in one direction, means for rotatably supporting said lower wheel on said frame, means for rotating said lower wheel in the direction opposite to said first-mentioned direction and about an axis spaced from the axis of rotation of said disk, and a scraper secured to said upper wheel and extending approximately radially toward and over the upper surface of said annular disk to positively remove and continuously feed the work pieces from and back into the space between said lapping wheels, said scraper returning the work pieces again to the lapping wheels in the same succession in which they were removed and form ing a storage space with an annular area thereof.

3. A lapping machine according to claim 2 wherein said scraper is in the form of a strip of material having a slight curved portion'at each end thereof.

References Cited in the file of this patent UNITED STATES PATENTS 620,851 Morse Mar. 7, 1899 1,252,364 Schaum Jan. 1, 1918 1,264,928 Heim May 7, 1918 1,371,854 Buck Mar. 15, 1921 1,548,562 Spencer Aug. 4, 1925 

